Process of retting vegetable fibers.



UNTTED STATES 1 BERTRAND S. SUMMERS,

PATENT FlFICEt OF CHICAGO, ILLINOIS.

PROCESS OF RETTENG VEGETABLE FlBERS.

SPECIFICATION forming part of Letters Patent No. 696,515, dated April. 1, 1.902.

Application filed November 16, 1900.

To (bl/1 1071,0711 211'; may concern/.-

Be it known that I, BERTRAND S. Scnnnns, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Processes of Rotting Vegetable Fibers, of which the following is a full, clear, concise, and exact description.

My invention relates to a process of retting vegetable fibers, my object being to provide improved means for removing the gum from the fibers and separating the same into the constituent filaments without impairing the integrity of the filaments or of the ultimate :fibers composing the same.

Vegetable fibers-such as fiax,hcm p, ram ie, and the likeconsist, usually, of a central tube or core of ligneous material having a bore which is filled with pith. Upon the exterior of this tube of ligneous material are the vegetable fibers, and surrounding the vegetable fibers is a thin skin. In preparing the vegetable fiber for use in the textile arts the fibrous material between the exterior of the ligneous tube and the outer skin is the portion which is utilized. The pith usually dries up and disappears when the stalk has been cut and the ligneous tube or core is broken and removed to leave the fibrous material in the form of one or more ribbons, according to the number of longitudinal lines along which this layer of fibrous material is split in separating the same from the ligneous tube or core. The skin usually adheres to the ribbon and during the hackling of thefiber disappears in the form of a fine dust. This fibrous material consists of a mass of filaments lying side by side and held together by gummy cementing material. The filaments are themselves composed of short fine fibers, which are likewise bound together into the filament by means of cementing material. In preparing the vegetable fiber for use in the textile arts the filaments are to be separated by the removal of the gummy cementing material without breaking up the filaments into the ultimate fibers. The most successful process of retting the fibers as prac- L ticed heretofore has been the so-callcd natural rot, in accordance with which the stalks are placed in the bed of a river having the peculiar retting properties-as, for instance,

Serial No. 36,698, (No specimens.)

in the river Lis, in Belgium-or by subjecting the fibers to the retting action of the weather by distributing the stalks over the ground in position to be acted upon by the rain and moisture to thereby remove the gum. It has also been proposed to remove the gum by artificial means, as by the use of chemical and other solutions; but these solutions have had the general effect of deteriorating the fibers. \Vhen the natural ret is employed, the resultant fibers are soft, silky, and resilient, thus possessing tone and quality, whereas the chemical solutions seem to remove certain ingl'edients not affected by the natural ret, leaving the fibers in a more or less harsh condition. Ithas also been proposed to employ boiling water alone for retting the fibers; but it has been found that water, as well as the solutions of chemicals, removes certain ingredients which are left in the fiber by the natural process and which ingredients impart to the fiber the tone and quality above referred to.

It is the object of the present invention to provide an artificial process which will serve to ret the fibers and remove the cementinggum, while leaving in the fibers the ingredients which have been found essential or desirable for imparting to the fiber the necessary tone or quality. In accordance with the present invention I employ a solution of liquid, preferably Water, having an avidity for the gums which serve to cement the filaments together, said liquid being saturated wholly or in part with the ingredients or materials which are essential for imparting the tone and quality to the completed fiber, this saturation being to a degree which will prevent the deleterious removal of such ingredients from the fibers to be retted and will give a product of the desired grade. Besides the gums, which serve to bind the filaments together, there are certain ingredients, which appear to be of an oily waxy nature, present in the vegetable fiber which impart to the completed fiber the desirable softness and silkiness known in the art as tone, quab ity, or nature, and when these oily and waxy ingredients are removed the resultant fiber is harsh and dry and loses its nature. In practicing myinvention, therefore, I saturate the retting solution with the oily and waxy ingredients which it is desired to retain in the completed fiber, so that when the fiber to be retted is subjected to the action of the solution the solution will remove the gums to thereby separate the filaments, but will leave intact the oily or waxy ingredients. The gums which are to be removed are of a peetose nature, and I find that ordinary water has an avidity for these gums and is capable of taking the same into solution. I preferably employ soft Waterthat is, rain-water or water thathas been distilled. Soft Water is free from chemicals, and the fibers are thus not subjected to any chemicals which might deleteriously affect them.

In preparing the solution I preferably secure the desired saturation or impregnation with the oily and waxy ingredients by subjecting an initial mass of the particular Vegetable fiber which is to be operated upon to the action of fresh water, the water being subjected to heat to facilitate and expedite the operation. The water will remove from the vegetable fibers not only the gums and substances of pectose nature, but will also remove the oily and waxy ingredients. When the fiber has been subjected to the action of the water fora sufficient period of time to saturate the water to the desired degree with the oily and waxy ingredients, I subject the saturated or impregnated solution to the action of a precipitant, which will be more particularly described hereinafter, which has the effect of depositing the gums and substances of apectose nature, but which does not deposit the oily and waxyingredients, the same being left in solution. The deposited gum may then be removed from the solution by filtration. The resultant solution is a solution which is saturated with oils and waxes and which has an avidity or appetite-for the gums and substances of pectose nature. The degree of avidity of the retting solution may be regulated by the extentofprecipitation and filtration. By removing more or less of the gum from the solution the avidity may be adjusted to the required degree. The initial mass of vegetable fiber having lost its oily and waxy ingredients is of course rendered useless for textile purposes and is discarded. When, therefore, a new batch of the vegetable fiber is subjected to the action of this solution, the solution will absorb and remove the cementing-gum, but will not remove the oils and waxes, since the solution is saturated with such oily and waxy ingredients. When the fibers have been subjected to the action of this solution for a suflicient length of time, usually two hours, under the action of heat to thoroughly remove the desired quantity of the gum, the fibers are withdrawn from the solution and prepared in the usual manner for use in the arts. The gums which have been taken up by the retting solution may be deposited by adding thereto the precipitating chemical hereinafter described, and the precipitated gum may be filtered from the solution to leave the solution active and in condition to rot a fresh batch of the fiber. The same solution may thus be employed repeatedly for action upon the fibers and after each operation or at suitable intervals the gum may be removed therefrom.

'As the solution is employed for repeated operations a certain amount of the solution will disappear by soaking into the fiber being retted. This will necessitate the addition of a small quantity of water at the end of each operation or at frequent intervals, and this added water would tend to lower the saturation of the liquid with the oily and Waxy materials unless some means were provided for replenishing the liquid with such oily and waxy materials. The skin of the stalk which surrounds the ribbon contai-nin g the filaments is made up in great measure of oily and waxy materials. This oily and waxy material is readily yielded and may serve to replenish the oily and waxy ingredients in the solution. W'hen the fibers are removed from the solution and prepared, this skin disappears in the form of a fine dust, so that the removal of the oil and waxes therefrom does not affect the integrity of the resultant fiber.

Instead of relying upon the oily and waxy ingredients in the skin for replenishing the solution a separate batch of the fiber may be continuously subjected to the liquid, whereby the liquid may take up from this supplemental batch of material such oily and waxy ingredients as may be necessary to replenish the lost oily and Waxy ingredients. When the oily and waxy ingredients have been completely withdrawn from this supplemental batch of material, the same may be discarded and a new batch placed in position. A further means of replenishing the solution to take the place of that which soaks into the fibers is to have a separate reservoir containing the retting solution, from which quantities may be withdrawn from time to time and passed to the circulating system to replace the portion of the solution removed.

I will now describe that step in the process which consists in removing the gum from the retting solution. IVhen the fiber has been subjected to the retting solution for a period, the solution loses its appetite for the gum, and in order to render this solution active again it is necessary to remove this gum. In practice the quantity of the fiber to be acted upon and the quantity of the retting solution will be so adjusted relatively that the solu tion will serve to remove all of the gum required before the same loses its retting power. To remove the gum from the retting solution, I employ a chemical which has the property of precipitating the gums and materials of a pectose nature, While not disturbing the oils and waxy materials. For this purpose lead oxid, barium sulfate, tin chlorid, lime, or

other similar agent may be employed. I preferably employ lead oxid (litharge) for the precipitant materialon account of its efficiency,

relative cheapness, and because, being in a solid andinsoluble form, it can be readily removed from the retting solution after it has performed the precipitant function, A soluble substance, such as lime and stannous chlorid, while effectively precipitating the solution, requires considerable care and atten tion to remove the traces thereof from the solution after the precipitation takes place. This removal adds to the expense of the process, and failure to remove the same may atfeet the natureof the fibers. The litharge, however, being solid and insoluble, may be commingled with the solution to thoroughly precipitate the gums and substances of pectose nature, and the solution may then be filtered, whereby the gum and the litharge will be separated from the solution.

To remove the litharge and to separate the same from the gum, so that the litharge may be again used, the gum may be burned by placing'the mixture upon a heated surface, as upon a metal plate resting'over a fire, and the gums will thus be burned and destroyed, leaving the litharge, which maybe again employed for precipitating the gum from the solution.

In practice I preferably subject the retting solution to the lit-barge in a chamber provided with means for agitating the litharge and the solution. The litharge is thus thoroughly com mingled with the solution and produces an effective precipitation, and as the solution passes from the agitatingchamber its direction of movement is repeatedly reversed, whereby the litharge is separated therefrom, so that the litharge remains in the agitatingchamber, while the solution with the precipitated gum held in suspension is permitted to pass therefrom. The solution containing the gum in the form of a precipitate may then be passed through a filter, such as asbestos, which serves to separate the gum from the solution. By thus preventing the litharge from passing to the filter the clogging of the filter by the solid litharge is avoided, and the gum may be recovered as a by-product. For these reasons I preferably produce the precipitation in a chamber separate from that in which the filtration takes place, although, as above set forth, the precipitation and filtration may be performed at the same time in a single chamber.

The avidity of the retting solution for the gums may be regulated as desired by regulating the quantity of gum removed from the solution by precipitation and filtration.

It will be understood that if the fiber is to be of the best grade the retting solution should be practically completely saturated with the oily and waxy ingredients, so that lit tle or none of these ingredients will be removed t'rom the fibers operated upon. For fibers which are to be of lower grade, however, the saturation need not'be carried to this extreme, but the retting solution may be impregnated with the oilyand waxyingredients to the desired degree to preserve in the completed fiber the proper amount of oily and waxy ingredients. The retting solution may thus have its solvent appetite or avidity for the ingredients to be retted satisfied wholly or in part and to the desired degree to pro duce completed fibers of the desired grade. In the formation of the retting solution the subjection of the fibers to the water serves to place the oily and waxy ingredients in a solvent relationto the retting liquid; but whether this solution. is wholly chemical or is partially physical in its nature I am unable to state. It is a fact, however, that the oily and waxy ingredients go into the solution and do not form merely an emulsion, since in the latter case the solvent appetite or avidity of the retting liquid for the oily and waxy ingredients would not be diminished, whereas with the retting liquid as produced in accordance with my invention the solvent action of the retting liquid upon the oily and waxy ingredients is determined by the extent to which the saturation or impregnation is carried.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The herein-described process of retting vegetable fibers, which consists in subjecting the same to the action of an agent having an appetite or avidity fortheingredients sought to be removed, and having its solvent appetite or avidity for theingredients, the presence of which lends quality and nature to the completed fiber, satisfied wholly or in part, whereby one class of ingredients is removed while the other remains intact, substantially as described.

2. The herein-described process of retting vegetable fibers, which consists in subjecting the same to an agent capable of removing the gummy cementing materials, and having its solvent avidity for the oily and waxy ingredients, which lend quality or nature to the completed fiber, satisfied wholly or in part, substantially as described.

3. The herein-described process of retting vegetable fibers which consists in subjecting the same to the action of a liquid having an avidity for the gummy cementing materials and having its solvent avidity for the ingreclients of an oily or waxy nature which it is desired to retain in the completed fiber satisfied wholly or in part, substantially as described.

4. The herein-described process of retting vegetable fibers, which consists in subjecting the same to the action of water having its sol vent avidity for the ingredients which it is desired to retain in the completed fibers satisfied wholly or in part, substantially as described.

5. The herein-described process of rotting vegetable fibers, which'consists in'subjecting the same to the action of water having its solvent avidity for the ingredients of an oily and g waxy nature which it is desired to retain in the completed fiber satisfied wholly or in part, substantially as described.

6. The herein-described process of retting vegetable fibers, which consists in subjecting an initial mass of the particular vegetable fiber to be retted to the action of the liquid which is to form the retting solution to saturate or impregnate the same with the oily and waxy ingredients and then subjecting the vegetable fibers to be retted to the action of said solution, substantially as described.

'7. The herein-described process of retting vegetable fibers, which consists in subjecting an initial mass of the particular vegetable fiber to be retted to the action of the liquid which is to form the retting solution to remove the gummy material therefrom and to saturate or impregnate the same with the oily and waxy ingredients, subsequently extracting the gummy material from said liquid and leaving the same saturated or impregnated with the oily and waxy materials, and then subjecting the vegetable fibers to be retted to the action of the said solution, substantially as described.

8. The herein-described process of retting vegetable fibers, which consists in subjecting an initial mass of the particular vegetable fibers to be retted to the action of the liquid which is to form the retting solution to remove the gummy material therefrom and to saturate or impregnate the same with the oily and waxy materials, subsequently extracting the gums from said liquid and leaving the same saturated or impregnated with the oily and waxy materials, subjecting the vegetable fibers to be retted to the action of said solution, and, finally, removing the gummy material from said rettin g solution to render the same again active and permit the employment of the same in the further retting of vegetable fibers, substantially as described.

9. The herein-described process of rendering an exhausted retting solution containing gummy, oily and waxy ingredients active, which consists in subjecting the same to the action of an agent to precipitate the gummy material while not affecting the oily and waxy ingredients in the retting solution, substantially as described.

10. The herein-described process, which consists in subjecting a retting solution containing gummy material and oily and waxy ingredients to the action of an agent capable of precipitating the gummy material without materially affecting the oily and Waxy ingre dients, and then removing said agent and said precipitated gummy materials from the solution, substantially as described. V

11. The hereindescribed process, which consists in subjecting a retting solution containing gummy material and oily and waxy ingredients to the action of an insoluble agent capable of precipitating the gummy material while not materially affecting the oily and waxy ingredients and then removing said insoluble agent and said precipitated gummy material from the solution, substantially as described.

12. The herein-described process, which consists in subjecting a retting solution containing gummy material and oily and waxy ingredients to the action of lead oxid to precipitate the gummy material and then removing said lead oxid and said precipitated gummy material from the solution, substantially as described.

13. The herein-described process, which consists in subjecting a ret-ting solution containing gummy material and oily and waxy ingredients, to the action of a practically insoluble agent capable of precipitating the gummy material While not materially aifecting the oily and waxy ingredients, removing the insoluble agent from the solution by mechanical separation and then removing the precipitated gummy material by filtration, substantially as described.

14. The herein-described method which consists in subjecting fibers of the kind to be retted to water to form the retting 1iquid, -re moving the gums from said liquid and then subjecting the fiber to be treated to the liquid thus formed to ret the same, substantially as described.

15. The herein described method which consists in subjecting fibers of the kind to be retted to the action of water under heat and pressure as set forth to form the rettingliquid, removing the gum therefrom, and then subjecting the fibers to be treated to the retting liquid thus formed under heat and pressure as set forth to ret the said fibers all substantially asdescribed.

In witness whereof I have hereunto subscribed my name in the presence of two witnesses.

BERTRAND S. SUMMERS.

\Vitnesses:

H. R. KINGMAN, W. CLYDE JoNEs. 

